Carbureter for internal-combustion engines



A. WEILAND.

CARBURETER FOR INTERNAL COMBUSTION ENGINES. APPLICATION, FILED JUNE5.1917.

1 83,044, Patented June 28, 1921.

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d %ENJT.OR Z

ATTORNEY.

UNITED STATES PATENT OFFICE.

ALFRED WEILAND, 0F PHILADELPHIA, PENNSYLVANIA.

GARBURETER FOR INTERNAL-COMBUSTION ENGDTES.

Specification of Letters Patent.

Application filed June 5, 1917. Serial No. 172,847.

certain new and useful Improvement in Carbureters forInternal-Combustion Engines, of which the following is a specification.

The present invention relates to carbureters for explosive engines andhas particular reference to the feedin offuel to the carbureter, theproper mixing of the fuel with air to form an efi'ective explosivemixture under varying engine conditions and the automatic control of themixture propor: tioning means in accordance with the demands of theengine under working conditions.

An object of the invention is to provide a carburetor wherein thecarbureting chamber under operating conditions is alwa s supplied withfuel in proper amount wit out the aid of a float or floats as in the.ordinary construction.

- A further object of the invention is to provide means for not onlymaintaining an available supply of liquid fuel for use in thecarbureting chamber but also to regulate the quantity of fuel deliveredfrom said supply to the mixing chamber according to the requirements ofthe motor as determined by the negative pressure of the motor intake.

F or the purpose of illustrating my invention, I have shown in theaccompanying drawings one form thereof which is at present preferred byme, although it is to be understood that the various instrumentalitiesof which my invention consists can be variously arranged and organizedand that my invention is not limited to the precise arrangements andorganization of the instrumentalities as herein shown and described.

Referring to the drawings:

Figurel represents avertical section of a carbureter embodying myinvention.

Fig. 2 represents a section on line 22 of Fig. 1. F Fig. 3 represents asection on line 3-3 of l designates generally the casingof thecarbureter the same forming a transverse passage serving as thecarbureting chamber 2, one end of which is connected to and forms partof the motor intake, while the opposite end is open to the atmosphereand forms the main air inlet. This inlet, in the present instance, iscontrolled by a valve 3 of the flap type which is pivoted for movementwith a rock spindle 4 under the control of the exterior lever 5, as willbe understood. As here shown the valve 3 is normally maintained in apredetermined open position by the provision of a'spring 6 which isconnected at one end to the lever 5 and at the other end to an adjustingscrew 7 which is mounted in a lug 8 fixed to the casing. By thisconstruction, the tension of the spring may be adjusted to meetrequlrements and is preferably always under sufiiclent tension tomaintain the valve 3 open a predetermined amount for the passage of air,while a further opening of the valve takes place in accordance with theamount of negative pressure in the motor intake.

9 designates the throttle valve which is pivotally mounted in thecarbureting chamber 2 to control the mixture in the required manner and,as here shown, is provided with a tubular body part 10 which receives atone end the sleeve extension 11 of a dash-pot cyl nder 12 and at theopposite end a fuel dellvery tube 13. The extension 11 is fixed to thethrottle valve 9 by the pin 14 or equivalent means, so that as it isturned from one position to another by the throttle lever 15 itsmovement is transmitted to the throttle valve and the latter shifted inthe desired manner. The cylinder 12 is of ordinary open endedconstruction closed by the cap 16 and this latter carries an adjustablethumb screw 17 which passes through the cap and terminates adjacent toand in the path of movement in one direction of the plunger 18, so thatthe latter, under certain conditions, will contact with the screw 17 andbe limited in its movement. In this connection, it will be noted thatthe abutting end of the thumb screw is provided with a port 19 for thepurpose of establishin communication between one side of the p unger 18and a conduit 20 even though the dash pot is in seated position againstthe said screw 17. The conduit 20 is formed in a tubular. stem 21 andextends to approximately the central portion of the tubular body 10 ofthe throttle valve where it com- Patented June 28, 1921.

' muni'cates with transverse ports 22' which i open into an annularspace 23 formed between the juxtaposed endsof the stem 11 and tube 13.This space has communication with the carbureting chamber by way of theopenings 24. The stem 21 is constructed to pass through a portion of thetube 13 and terminates in an enlarged head portion 25 which is arrangedto slide freely within the chambered portion 26 of the tube 13. Thatportion of the stem 21 which passes through the tube 13 forms in effecta valve, since for a portion of its length, it is tapered, as indicatedat 27, to' conform to a similarly tapered part "of the tube 13 whichforms the valve seat 28, though in actual operation, it will beunderstood that the valve 27 is not adapted to entirely close theopening or passageway 29 and will hereinafter be described. Thus thepassage 29 and openings 24 form the fuel jet of the carbureter, and thearrangement is such that in any open position of the throttle valve 9,the fuel jet will be directly subject to the maximum negative pressurein the motor intake. The head 25 is provided with a port 30 forming anormally open passage or means of communication between the portion 26and the auxiliary fuel reservoir 31.

This latter, in the present instance, is formed in a supplemental casing32 attached to and depending from the main casing 1, though it will beunderstood that this is merely for purpose of illustration and anyequivalent means for forming the reservoir 31 as a part of the casing 1may be employed.

33 designates the fuel inlet to the reservoir 31 the same beingpreferably formed in the wall of the casing 32 above the inlet of theport 30 in order that the liquid fuel may collect in the reservoir 31and act, under certain conditions, as a seal for the port 30, as will belater explained. The inlet 33 has free communication by way of the pipe34 with thechamber 35 of a receiving tank 36 and, as here shown, thiscommunication is established by way of a tube 37 which extends anappreciable distance within the chamber 35. The main fuel supply isstored in the tank 38 which communicates directly by way of the pipe 39'with the chamber 35 and its supply of liquid fuel to the said chamber 35may be either by gravity or by suction according to the position of thepipe 39. 40 designates a pipe passing through the delivery tube 37 andserving to conduct air under atmospheric pressure below the level of theliquid fuel supply in chamber 35 whereby the said fuel is raised throughthe delivery tube 37 and pipe 34 to the main reservoir 31 on theprinciple of an air lift pump. In order to introduce air to the pipe 40,there is a port 41 suitably formed for the purpose and the quantity ofair may be regulated by an ad ustable needle valve 42 arbring the airvalve 42 and air port 41 well above the level of the supply tank 38andpreferably located at the same level as the carbureter itself, sothat there will be no danger of the liquid fuel overflowing through theport 41 under all normal operating conditions.

Before consldering the operation of the carbureter, it should be notedin connection with the dash-pot construction, that the plunger 18 andits adjuncts are normally under the pressure of a spring 43 which tendsto maintain the valve 27 in open position so that there is always apassage for the liquid fuel to the motor intake when the motor is inoperation, though this passage may be restricted automatically accordingto the negative pressure in the motorintake and to variations in thisnegative pressure. A port 44 or the like is provided to relieve thepressure in the cylinder 12 at the opposite side of the plunger 18 fromthe spring 43, as will be understood.

In the operation of the carburetor, the air valve 3 is adjusted, byproperly tensioning the spring 6-, to maintain an air inlet suitable fora predetermined minimum negative pressure in the motor-intake, andconsequently, a condition exists which gives a mixture rich in fuelandavailable for starting and slow speed conditions. Thus the negativepressure of the motor-intake causes the liquid fuel to be drawn throtghthe passage 29 to the space 23 and thence discharge into the carburetinmixes with" the air from the main air inlet. The location of the ports24 at points spaced from the walls of the chamber '2 gives a moreintimate and complete mixing with the air than where such orts are inthe walls of the carbureting c amber or in such close proximity theretoas to cause particles of the liquid to adhere to the walls instead ofmixing directly with the body of air.

Considering conditions, when the negativepressure is increased, eitherby load conditions or by use of the throttle, it will be chamber '2,where it evident that the pressure at the spring side of the dash-potplunger 18 is also reduced, since the conduit 20 forms a directcommunication with the motor-intake, and acts to overcome the tension ofthe spring 43, thus shifting the stem 21 and causing the fuel dischargepassage 29 to become restricted sufimportant feature in the operation ofthe feeding offuel to the carbureting chamber, since it regulates thequantity of fuel to be delivered for forming the explosive mixtureposition Where the passage 29 is increased and more fuel is delivered tothe motorintake. Another feature of this construction is in theprovision of the head 25 with the inlet to the. port 30 adjacent to orsubstantially at the level of the liquid fuel in the reserve reservoir31. Since this latter has no direct communication with the atmosphere itis always subject to the negative pressure of the motor-intake, andconsequently, as the increments of the fuel are drawn to the motor theywill be automatically'replaced by liquid fuel mixed with air drawnthrough-the pipe 34. Under conditions where the motor is at rest, theinlet of the port 30 is submerged and is therefore liquid sealed toprevent air under atmospheric pressure from entering the reservereservoir 31 by way of the passage 29 and thereby disturbing conditionsin the pipe 34 and reserve chamber 35. Under running conditions,however, the inlet to the port 30 may or ma not be sealed by the liquidsince, if sealed, the negative pressure causes air to bubble through thefuel to carry fuel to the carbureti'ng chamber, and if unsealed, thesaturated air from pi e 34 passes to the carbureting chamber directlythrough port 30. Naturally, the submergence of the port 30 means amixture rich in fuel and therefore the construction is designed withaView to giving the desired submergence at a time when the speed or loadrequires a mixture rich in fuel.

It will now be apparent that I have devised a complete unitarystructure, wherein the use of a float for controlling the fuel level isdispensed with while the device in operation effectivelysregulates thesupply of' fuel and the explosive mixture in accordance with the speedand load conditions imposed upon the motor.

It will now be apparent that I have devised a novel and usefulconstruction which embodies the features of advantage enumerated asdesirable in the statement of the invention and the above descriptionand while I have in the present instance shown and described thepreferred embodiment thereof which has been found in practice to givesatisfactory and reliable results, it is to be understood that thesameis. susceptible of modification in various particulars without departingfrom the spirit or scope of the invention or sacrificing any of itsadvanta es.

IVhat I claim is:

1. In a device of the character stated, a

casing forming acarbureting chamber, having communication with theatmosphere and with the intake of a motor of the explosive type, areservoir for liquid fuel, a movable fuel conducting means forming acommunication between said reservoir and said carbureting chamber andmeans for submerging the inlet of said fuel conducting means in the bodyof fuel in said reservoir under conditions producing a decreasednegative pressure in the motor intake.

2. In a carbureter, a casing forming a carbureting chamber havingopposite ends re spectively in communication with the atmosphere and theintake of a motor of the explosive type, a fuel reservoir, means formmga fuel conduit between said reservoir and said chamber, a reciprocablevalve in said conduit having a passage therein for controlling the fuelsupply to said chamber, a throttle valve arranged to controlthedischarge of fuel to said chamber, means to automatically regulate thesupply of air to said chamber, and means arranged to sub-, merge theinlet of said valve passage under inoperative conditions.

3. Ina carbureter, a casing forming a carbureting chamber communicatingat opposite ends respectively with an air supply and with the intake ofa motor of the explosive type, a fuel reservoir, a fuel valve arrangedto control the passage of fuel to said carbureting chamber, said valvehaving a passage therethrough, and means operative by pressureconditions in the motor intake for reciprocating said valve to regulatethe supply of fuel under operating conditions and to holdthe inlet ofsaid valve passage submerged under inoperative conditions.

4. In'a carbureter, a casing forming a carbureting chamber arranged tocommunicate with the atmosphere and with the intake of an internalcombustion engine, a fuel reservoir, a fuel nozzle arranged to dischargefuel into said carbureting chamber and having a portion extending intosaid reservoir, a movable valve part for said nozzle arranged to traveltoward and away from the liquid level in said reservoir, said valve partbeing provided with a fuel passage having an inlet normally at the levelin said reservoir, and means controlled by variation of pressurein saidmotor intake for moving said valve part in a predetermined manner.

5. In a carbureter, a casing forming a carbureting chamber arranged tocommunicate with the atmosphere and with the intake of throttle valve soarranged as to' subject said an internal combustion engine, a fuelresernozzle to the maximum negative pressure of voir, a fuel nozzleextending from said ressaid. intake in any open position of said 10ervoir into said carbureting chamber and throttle, valve.

, having an inlet located in closeproximity to In testimony whereof Ihave hereunto the liquid level in said reservolr, means for signed myname. varying the location of said inlet, and a ALFRED WEILAND.

